Flux-cored electrodes are in widespread use in the field of arc welding steel where such electrodes are continuously fed to an arc for accomplishing a desired deposit on a workpiece. As such electrodes are uncoated or "bare" , direct electrical contact may be made with the exterior of the electrode to provide the electrical energy that sustains the metal melting arc. In general, a flux-cored electrode includes an external sheath which encloses a core including a wide variety of fluxes, deoxidizers, and slag-forming ingredients along with alloying metal. A truly large number of different flux-cored electrodes have been proposed in the past, even when considering only mild steel electrodes for use on mild steel. However, a vast quantity of such electrode is used by industry, particularly in heavy fabrication, the manufacture and repair of construction equipment, ship building, and for offshore structures. Consequently, with regard to various criteria, a need continues to exist for an improved form of such welding electrode.
In considering any specific form of a welding electrode, the chemical composition of the resulting deposit is generally defined. Specifically, with respect to the electrode of AWS classification E70T-1, the deposited weld metal must comprise iron along with the indicated maximum percentages by weight of the following metals: manganese 1.75%, silicon 0.90%, nickel 0.30%, chromium 0.20%, molybdenum 0.30%, and vanadium 0.08%.
Apart from the requirement of the chemical composition of a standardized electrode, requirements also exist for various mechanical properties, weights, and sizes. Again with regard to the AWS classification E70T-1, various diameters may conform; however, the electrode of the present invention is restricted to a diameter of approximately 3/32" based on the establishment of a specific form of electrode which affords considerably improved performance and economy within a specific classification.
Recognizing that the weld deposit of a standard electrode classification must conform to specific requirements, the possible variations of size and content of the electrode nevertheless might approach infinity. In general, the need exists for an electrode which meets the standard of AWS classification E70T-1 and which has good weldability and mechanical properties with major improvement in efficiency or deposition rate, pounds per hour. In general, the present invention is directed to a standard AWS classification E70T-1 electrode which has a deposition rate that is substantially increased with respect to conventional electrodes that conform to the AWS classification E70T-1.